Summary: Outlook attachment “array index out of bounds” is a frustrating error which an user faces. It is something you are not ready for, as this happens suddenly especially when you open, preview, or download your emails. This article will heavily focus on its prominent steps to resolve Outlook indexing not working issues.
What is the Array Index out of Bounds Error?
Array is actually your collection of data which is stored in your memory part. This error occurs usually when you download any unknown add-ins, and they try to access information outside the available data range.
Scenario:
Outlook wants 10 attachment records, but is trying to access the 11th record. Since, there is no such record, it throws the “Array Index Out of Bounds” error.
Similar Error Like this:.
You may face same error message but in different form:
- Array index out of bounds exception
- Index out of range issue
- Outlook encountered an unexpected error
- Application has stopped working when trying to open attachment
Even though the lines may be different, the methods to resolve them are the same.
Also, you can check this blog on how to fix Outlook drag and drop not working issues.
Reasons Behind Outlook Attachment Array Index out of Bounds Problem
These are some of the points why users face Outlook indexing not working issues.
- It can be because of your corrupted Outlook profile
- Your attachments will not open, and shows you an Array Index Out of Bounds error
- Due to damaged mailbox files which could lead to errors in accessing your attachments
- Installing unknown add-ins in Outlook will block the attachment process
- An issue with the Outlook search index can affect your Outlook performance
- Having problems with the Windows Search index could affect your find and preview option
- Because of large-size mailboxes, you could face the risk related to indexes and attachments
- There are chances that software errors in some updates for Outlook might cause problem
- Sometimes, you have not given the permission to access its temporary attachment folder
Outlook Indexing Not Working – Signs Users Ignore
Many users ignore the issue of index because it is not associated with attachments.
This is what you need to look out for:
- No results on searching
- Recently sent messages not shown
- Attachments not found
- Outlook search still “searching..”
- Search is very slow
- Attachment preview is unsuccessful
In case you experience the above problem along with the Array Index Out of Bounds error. The first step should be to re-index the search.
Manually Resolve Outlook Attachment Array Index out of Bounds Error – 8 Ways
Follow these simple ways to solve these Outlook problems. Just go with all these to maintain attachment flow.
#1. Restart your Outlook
There can be one-time problems with memory that could lead to Outlook issues.
- First, close your running Outlook application
- Restart your entire PC
- Then, open your Outlook one more time
- Now, try to open the attachments again
This is the basic way to start with.
#2. Run Outlook in Safe Mode
If you open your attachments in Safe mode, then you might not face Outlook attachment array index out of bounds problem. As, it blocks third-party plug-ins.
1. Firstly, press Windows + R shortcut key.
2. There, type this below command:
outlook.exe /safe

3. Click Enter.
4. Now you can open the attachment.
If the problem disappears, an Outlook plug-in is responsible for that problem.
#3. Disable Problem Add-ins
- Just launch Outlook
- From the File menu, select Options > Add-ins
- Choose COM Add-ins
- Click on Go
- There, uninstall all add-ins
- Close and reopen Outlook
Now, activate add-ins one by one to find out which one is causing problems.
#4. Repair Outlook Data File
In case there is corruption in your PST file, you can follow this guide to fix it using the Inbox Repair Tool which is an in-built feature of Microsoft.
Find:
- SCANPST.EXE
- Launch it
- Choose your PST file
- Next, click on Start
- It will start repairing your mailboxes
- After completing, restart Outlook
#5. Create a New Outlook Profile
It is because your current profile is damaged, and this is the reason behind the issue.
- Open Control Panel > Mail > Show Profiles > Add.
- Set up your account
- Make the profile the default one
- Run Outlook again
#6. Fix Microsoft Office
Outlook files may get corrupted at times.
- Open Control panel
- Go to programs and features
- Over there, click on Microsoft Office
- There, tap on Change
- Select Quick Repair button
If resolved well and good. In case, it’s not you can use Online Repair after this.
#7. Rebuild Outlook Search Index
As you know, indexing issues may show you Outlook indexing not working issues. So, this step is very important.
- At first, open Control Panel
- Look for Indexing Options
- There, click on Advanced tab
- Select Rebuild
- It will take some time for the process to finish
- Once it is done, restart Outlook
#8. Remove Outlook Temporary Files
1. When you open an attachment in Outlook, it is stored in a temporary folder.
2. What If your temporary folder gets damaged:
- Your attachments will not open
- Preview is not possible
- Array error may be seen
Deleting those temporary files will help solve the problem of Outlook attachment array index out of bounds.
Limitations of Using Manual Steps
The methods will work in terms of Outlook, but they do not solve the user’s problem of dealing with a huge number of attachments.
- Attachments in thousands all over the folders
- Hard to find necessary attachments
- Need to download attachment one by one
- There is lots of duplicate files which takes more space
- Huge mailbox tends to slow down your Outlook
- Need to filter attachments according to the date, sender, or file type
Thus, working only with Outlook is time-consuming. So, we have come up with an automated solution for you.
Use Professional Solution to Manage & Extract Outlook Attachments
After resolving the “Outlook Attachment Array Index Out of Bounds” issues, users tend to face difficulties in managing multiple attachments. This is where SysTools Outlook Attachment Extractor Software comes in. It enables you to extract attachments from Outlook PST, & OST files in bulk rather than saving them individually. Moreover, this tool also allows you to filter attachments by date, sender, subject, attachment type, or size.
Best Practices:
In order to lower the risks of experiencing problems with Outlook attachments:
- Keep your Outlook up-to-date
- Do not include large PST file
- Archive your old messages time to time
- Delete attachments which you don’t need
- Restore the search index for Outlook issues
- Uninstall extra add-ins
- Take backup while performing
- Maintain proper functionality of Windows Search
End Note
Users are facing errors like Outlook attachment “Array Index Out of Bounds”. It is generally associated with mailbox corruption, add-ins for Outlook, profile corruption, or non-functioning of Outlook search indexing. All these methods may become difficult with big mailboxes. In order to manage your Outlook Attachments, there is a tool mentioned above that can make your work easier.